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<li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_3a90233651aeb6de4309a51b31e57ac6.html">omp</a></li>  </ul>
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<a href="omp_2mapreduce_8h.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno">    1</span>&#160;</div><div class="line"><a name="l00021"></a><span class="lineno">   21</span>&#160;<span class="preprocessor">#ifndef GRPPI_OMP_MAPREDUCE_H</span></div><div class="line"><a name="l00022"></a><span class="lineno">   22</span>&#160;<span class="preprocessor">#define GRPPI_OMP_MAPREDUCE_H</span></div><div class="line"><a name="l00023"></a><span class="lineno">   23</span>&#160;</div><div class="line"><a name="l00024"></a><span class="lineno">   24</span>&#160;<span class="preprocessor">#ifdef GRPPI_OMP</span></div><div class="line"><a name="l00025"></a><span class="lineno">   25</span>&#160;</div><div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;<span class="preprocessor">#include &quot;<a class="code" href="parallel__execution__omp_8h.html">parallel_execution_omp.h</a>&quot;</span></div><div class="line"><a name="l00027"></a><span class="lineno">   27</span>&#160;</div><div class="line"><a name="l00028"></a><span class="lineno">   28</span>&#160;<span class="keyword">namespace </span><a class="code" href="namespacegrppi.html">grppi</a> {</div><div class="line"><a name="l00029"></a><span class="lineno">   29</span>&#160;</div><div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;<span class="keyword">template</span> &lt;<span class="keyword">typename</span> InputIt, <span class="keyword">typename</span> Transformer, <span class="keyword">typename</span> Result, </div><div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;          <span class="keyword">typename</span> Combiner&gt;</div><div class="line"><a name="l00055"></a><span class="lineno"><a class="line" href="group__mapreduce__pattern__omp.html#ga89a89292c1dcdaae36d5a7f5bcfa6287">   55</a></span>&#160;Result <a class="code" href="group__mapreduce__pattern__native.html#ga7e52d3b07cbe4ae9928f2ad607d70e46">map_reduce</a>(<a class="code" href="classgrppi_1_1parallel__execution__omp.html">parallel_execution_omp</a> &amp; ex, </div><div class="line"><a name="l00056"></a><span class="lineno">   56</span>&#160;                    InputIt first, InputIt last, Result identity, </div><div class="line"><a name="l00057"></a><span class="lineno">   57</span>&#160;                    Transformer &amp;&amp;  transform_op,  </div><div class="line"><a name="l00058"></a><span class="lineno">   58</span>&#160;                    Combiner &amp;&amp; combine_op)</div><div class="line"><a name="l00059"></a><span class="lineno">   59</span>&#160;{</div><div class="line"><a name="l00060"></a><span class="lineno">   60</span>&#160;  <span class="keyword">using namespace </span><a class="code" href="namespacestd.html">std</a>;</div><div class="line"><a name="l00061"></a><span class="lineno">   61</span>&#160;  Result result{identity};</div><div class="line"><a name="l00062"></a><span class="lineno">   62</span>&#160;</div><div class="line"><a name="l00063"></a><span class="lineno">   63</span>&#160;  std::vector&lt;Result&gt; partial_results(ex.<a class="code" href="classgrppi_1_1parallel__execution__omp.html#ac46ceef1db7f46cc7c93a2e1f4a43f08">concurrency_degree</a>());</div><div class="line"><a name="l00064"></a><span class="lineno">   64</span>&#160;<span class="preprocessor">  #pragma omp parallel</span></div><div class="line"><a name="l00065"></a><span class="lineno">   65</span>&#160;  {</div><div class="line"><a name="l00066"></a><span class="lineno">   66</span>&#160;<span class="preprocessor">    #pragma omp single nowait</span></div><div class="line"><a name="l00067"></a><span class="lineno">   67</span>&#160;    {</div><div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;      <span class="keywordtype">int</span> num_elements = distance(first,last);</div><div class="line"><a name="l00069"></a><span class="lineno">   69</span>&#160;      <span class="keywordtype">int</span> elements_per_thread = num_elements/ex.<a class="code" href="classgrppi_1_1parallel__execution__omp.html#ac46ceef1db7f46cc7c93a2e1f4a43f08">concurrency_degree</a>();</div><div class="line"><a name="l00070"></a><span class="lineno">   70</span>&#160;      <a class="code" href="classgrppi_1_1sequential__execution.html">sequential_execution</a> seq{};</div><div class="line"><a name="l00071"></a><span class="lineno">   71</span>&#160;</div><div class="line"><a name="l00072"></a><span class="lineno">   72</span>&#160;      <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i=1;i&lt;ex.<a class="code" href="classgrppi_1_1parallel__execution__omp.html#ac46ceef1db7f46cc7c93a2e1f4a43f08">concurrency_degree</a>();i++) {    </div><div class="line"><a name="l00073"></a><span class="lineno">   73</span>&#160;<span class="preprocessor">        #pragma omp task firstprivate(i)</span></div><div class="line"><a name="l00074"></a><span class="lineno">   74</span>&#160;        {</div><div class="line"><a name="l00075"></a><span class="lineno">   75</span>&#160;          <span class="keyword">auto</span> begin = next(first, elements_per_thread * i);</div><div class="line"><a name="l00076"></a><span class="lineno">   76</span>&#160;          <span class="keyword">auto</span> end = (i==ex.<a class="code" href="classgrppi_1_1parallel__execution__omp.html#ac46ceef1db7f46cc7c93a2e1f4a43f08">concurrency_degree</a>()-1) ? last :</div><div class="line"><a name="l00077"></a><span class="lineno">   77</span>&#160;              next(first, elements_per_thread * (i+1));</div><div class="line"><a name="l00078"></a><span class="lineno">   78</span>&#160;          partial_results[i] = <a class="code" href="group__mapreduce__pattern__native.html#ga7e52d3b07cbe4ae9928f2ad607d70e46">map_reduce</a>(seq, </div><div class="line"><a name="l00079"></a><span class="lineno">   79</span>&#160;              begin, end, partial_results[i], </div><div class="line"><a name="l00080"></a><span class="lineno">   80</span>&#160;              std::forward&lt;Transformer&gt;(transform_op), </div><div class="line"><a name="l00081"></a><span class="lineno">   81</span>&#160;              std::forward&lt;Combiner&gt;(combine_op));</div><div class="line"><a name="l00082"></a><span class="lineno">   82</span>&#160;        }</div><div class="line"><a name="l00083"></a><span class="lineno">   83</span>&#160;      }</div><div class="line"><a name="l00084"></a><span class="lineno">   84</span>&#160;</div><div class="line"><a name="l00085"></a><span class="lineno">   85</span>&#160;      partial_results[0] = <a class="code" href="group__mapreduce__pattern__native.html#ga7e52d3b07cbe4ae9928f2ad607d70e46">map_reduce</a>(seq, </div><div class="line"><a name="l00086"></a><span class="lineno">   86</span>&#160;          first, first+elements_per_thread, partial_results[0], </div><div class="line"><a name="l00087"></a><span class="lineno">   87</span>&#160;          std::forward&lt;Transformer&gt;(transform_op), </div><div class="line"><a name="l00088"></a><span class="lineno">   88</span>&#160;          std::forward&lt;Combiner&gt;(combine_op));</div><div class="line"><a name="l00089"></a><span class="lineno">   89</span>&#160;<span class="preprocessor">      #pragma omp taskwait</span></div><div class="line"><a name="l00090"></a><span class="lineno">   90</span>&#160;    }</div><div class="line"><a name="l00091"></a><span class="lineno">   91</span>&#160;  }</div><div class="line"><a name="l00092"></a><span class="lineno">   92</span>&#160;</div><div class="line"><a name="l00093"></a><span class="lineno">   93</span>&#160;  <span class="keywordflow">for</span> (<span class="keyword">auto</span> &amp;&amp; p : partial_results){</div><div class="line"><a name="l00094"></a><span class="lineno">   94</span>&#160;    result = combine_op(result, p);</div><div class="line"><a name="l00095"></a><span class="lineno">   95</span>&#160;  } </div><div class="line"><a name="l00096"></a><span class="lineno">   96</span>&#160;  <span class="keywordflow">return</span> result;</div><div class="line"><a name="l00097"></a><span class="lineno">   97</span>&#160;}</div><div class="line"><a name="l00098"></a><span class="lineno">   98</span>&#160;</div><div class="line"><a name="l00104"></a><span class="lineno">  104</span>&#160;}</div><div class="line"><a name="l00105"></a><span class="lineno">  105</span>&#160;<span class="preprocessor">#endif</span></div><div class="line"><a name="l00106"></a><span class="lineno">  106</span>&#160;</div><div class="line"><a name="l00107"></a><span class="lineno">  107</span>&#160;<span class="preprocessor">#endif</span></div><div class="ttc" id="namespacegrppi_html"><div class="ttname"><a href="namespacegrppi.html">grppi</a></div><div class="ttdef"><b>Definition:</b> callable_traits.h:24</div></div>
<div class="ttc" id="namespacestd_html"><div class="ttname"><a href="namespacestd.html">std</a></div><div class="ttdoc">STL namespace. </div></div>
<div class="ttc" id="group__mapreduce__pattern__native_html_ga7e52d3b07cbe4ae9928f2ad607d70e46"><div class="ttname"><a href="group__mapreduce__pattern__native.html#ga7e52d3b07cbe4ae9928f2ad607d70e46">grppi::map_reduce</a></div><div class="ttdeci">Result map_reduce(parallel_execution_native &amp;ex, InputIt first, InputIt last, Result identity, Transformer &amp;&amp;transform_op, Combiner &amp;&amp;combine_op)</div><div class="ttdoc">Invoke Map/reduce pattern on a data sequence with native parallel execution. </div><div class="ttdef"><b>Definition:</b> native/mapreduce.h:53</div></div>
<div class="ttc" id="classgrppi_1_1parallel__execution__omp_html"><div class="ttname"><a href="classgrppi_1_1parallel__execution__omp.html">grppi::parallel_execution_omp</a></div><div class="ttdoc">OpenMP parallel execution policy. </div><div class="ttdef"><b>Definition:</b> parallel_execution_omp.h:40</div></div>
<div class="ttc" id="parallel__execution__omp_8h_html"><div class="ttname"><a href="parallel__execution__omp_8h.html">parallel_execution_omp.h</a></div></div>
<div class="ttc" id="classgrppi_1_1sequential__execution_html"><div class="ttname"><a href="classgrppi_1_1sequential__execution.html">grppi::sequential_execution</a></div><div class="ttdoc">Sequential execution policy. </div><div class="ttdef"><b>Definition:</b> sequential_execution.h:31</div></div>
<div class="ttc" id="classgrppi_1_1parallel__execution__omp_html_ac46ceef1db7f46cc7c93a2e1f4a43f08"><div class="ttname"><a href="classgrppi_1_1parallel__execution__omp.html#ac46ceef1db7f46cc7c93a2e1f4a43f08">grppi::parallel_execution_omp::concurrency_degree</a></div><div class="ttdeci">int concurrency_degree() const noexcept</div><div class="ttdoc">Get number of grppi trheads. </div><div class="ttdef"><b>Definition:</b> parallel_execution_omp.h:85</div></div>
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